This invention relates to medical electrode assemblies, and more particularly to electrode assemblies for use with external defibrillators.
Electrodes are used in a wide variety of medical applications. For example, electrodes are used with external defibrillators, to deliver a defibrillating shock to a patient.
Typically, two separate electrodes are applied to the patient for defibrillation treatments. In order for the defibrillating shock to be effective, it is important that the electrodes be positioned so that current flowing from one electrode to the other passes along a straight line that intersects or passes close to the patient""s heart (ideally through the ventricles). It is also necessary that good skin contact be made between the electrodes and the patient""s skin.
It may be difficult for lay or even skilled caregivers to position the electrodes correctly during emergency treatment. It may also be difficult to get good skin contact, particularly if the electrodes do not conform well to the body contours of the patient. Delay in correct positioning of defibrillator electrodes can mean the difference between life and death to a victim of cardiac arrest.
The invention features electrode assemblies that can be quickly and accurately positioned on a patient during emergency treatment, and provide good skin contact during use. The electrode assemblies are easy to use, and can be used by most lay caregivers. Moreover, the electrode assemblies of the invention are configured so that a single size electrode assembly can be used to effectively treat patients having a wide variety of chest sizes. In some implementations, the electrode assembly folds for convenient and compact storage.
The electrode assemblies of the invention are easy for lay and skilled caregivers to position quickly and accurately on patients of different sizes and shapes. The variation in the distance between the centerline of the chest and the mid-axillary line on the side of a person""s body (a measure of the person""s girth) in different individuals can be up to 8 inches or more. In preferred implementations the electrode assembly includes a separable electrode to compensate for these variations.
In one aspect, the invention features an electrode assembly for use with a defibrillator, including a pair of electrodes configured to be attached to a patient""s chest, to acquire data indicative of the patient""s heart rhythm and to deliver a defibrillating shock if appropriate, and a central member joining the electrodes, the electrodes being folded about the central member.
Some implementations may include one or more of the following features. The electrodes are folded along defined hinge regions. The electrodes are positioned about the central member to facilitate their placement on the chest in an optimal position for the delivery of defibrillation therapy. At least one of the electrodes is joined to the central member by a web of flexible material. The central member includes two portions that are foldable upon each other. The electrodes extend substantially transversely from opposite sides of the central member in a spaced relationship.
The electrode assembly may also include a CPR pad, mounted on the central member. Preferably, the CPR pad is configured to be pressed upon by a caregiver during the delivery of CPR chest compressions, and located on the assembly so that when it is placed on the patient""s lower sternum the defibrillation electrodes are properly placed for the delivery of defibrillation therapy. The CPR pad may include a sensor constructed to acquire data indicative of the depth and rate of CPR compressions.
One of the electrodes may be separable from the central member, to accommodate larger patients. The separable electrode may be joined to the central member by a separable flexible fastener, e.g., a separable hinge or hook and loop fastener tape.
The electrode assembly may also include indicia on an exposed surface of the electrode assembly, the indicia including a first portion and a second portion, the indicia being positioned so that alignment of the first portion with a patient""s nipples and alignment of the second portion with the patient""s sternum will correctly position the electrodes on the patient""s chest for effective defibrillation treatment. The indicia may be in the form of cross-hairs, and may be disposed on a CPR pad mounted on the central member or directly on a surface of the central member.
In another aspect, the invention features an electrode assembly for use with a defibrillator, including a pair of electrodes configured to be attached to a patient""s chest, to acquire data indicative of the patient""s heart rhythm and to deliver a defibrillating shock if appropriate; a central member joining the electrodes; and a CPR pad mounted on the central member, the CPR pad being contoured to receive a caregiver""s hand while the caregiver applies chest compressions to the patient.
Some implementations may include one or more of the following features. The CPR pad includes a concave upper surface shaped to facilitate placement of the caregiver""s hand. The CPR pad includes a convex lower surface shaped to conform to the patient""s sternal notch area. The CPR pad includes a sensor constructed to acquire data indicative of the depth and/or rate of CPR compressions.
In a further aspect, the invention features an electrode assembly for use with a defibrillator, including (a) a pair of electrodes configured to be attached to a patient""s chest, to acquire data indicative of the patient""s heart rhythm and to deliver a defibrillating shock if appropriate, (b) a central member joining the electrodes, and (c) an indicia on an exposed surface of the electrode assembly, the indicia including a first portion and a second portion, the indicia being positioned so that alignment of the first portion with a patient""s nipples and alignment of the second portion with the patient""s sternum will correctly position the electrodes on the patient""s chest for effective defibrillation treatment.
Some implementations may include one or more of the following features. The indicia may be located so that when the indicia are aligned with the nipples and sternum the indicia will indicate to a caregiver where the caregiver""s hands should be placed during the delivery of CPR chest compressions. The indicia may be disposed on the central member, or, alternatively, on a CPR pad, mounted on the central member.
The invention also features an electrode assembly for use with a defibrillator, including (a) an apex electrode and a sternum electrode, the electrodes being configured to be attached to a patient""s chest, to acquire data indicative of the patient""s heart rhythm and to deliver a defibrillating shock if appropriate; and (b) a central member joining the electrodes;
wherein one of the electrodes is separably joined to the central member.
Some implementations may include one or more of the following features. The separably joined electrode is the apex electrode. The separably joined electrode, after separation from the central member, is joined to the central member only by an electrical connector. The separably joined electrode is joined to the central member by a separable flexible fastener, e.g., a separable hinge or a hook and loop fastener tape. The separable hinge includes a locking pin constructed to be removed by a caregiver to separate the hinge.
In yet another aspect, the invention features an electrode assembly for use with a defibrillator, including (a) an apex electrode and a sternum electrode, the electrodes being configured to be attached to a patient""s chest, to acquire data indicative of the patient""s heart rhythm and to deliver a defibrillating shock if appropriate, and (b) a central member joining the electrodes, wherein the electrodes extend generally transversely from opposite sides of the central member in a spaced relationship.
Some implementations may include one or more of the following features. The electrodes are positioned about the central member to facilitate their placement on the chest in an optimal position for the delivery of defibrillation therapy. The electrodes are positioned about the central member to minimize contact of the electrodes with breast tissue of the patient. The apex electrode is joined to the central member by a hinge, allowing the apex electrode to be maneuvered around breast tissue. The central member is elongated. The electrodes have a combined active area of at least 150 cm2. Each electrode has an active area of at least 50 cm2, e.g., at least 75 cm2. The electrodes and central member define a xe2x80x9cstairstep-likexe2x80x9d shape. The central member is dimensioned to fit in the valley between the breasts of the patient. The electrodes extend substantially perpendicular to the central member.
In a further aspect, the invention features an electrode assembly for use with a defibrillator, including (a) a pair of electrodes configured to be attached to a patient""s chest, to acquire data indicative of the patient""s heart rhythm and to deliver a defibrillating shock if appropriate, (b) a central member joining the electrodes; and (c) a CPR pad positioned on the central member, the electrodes being folded about the central member in a manner so that the CPR pad is on top and can be grasped by a caregiver to unfold the electrode.
Preferably, the electrodes are folded in a manner so that when the CPR pad is grasped by a user the electrodes fall open in the general position in which the electrodes should be applied to the patient.
The invention also features an electrode assembly that includes (a) a pair of electrodes configured to be attached to a patient""s chest, to acquire data indicative of the patient""s heart rhythm and to deliver a defibrillating shock if appropriate, and (b) a central member joining the electrodes, the electrodes being folded about the central member and the electrode assembly further including labeling indicating how a caregiver should unfold the electrode assembly and apply it to a patient.
The labeling may include a series of graphics configured to illustrate the proper procedure for applying the electrode assembly.
In each of the aspects of the invention discussed above, the electrode assembly may further include lead wires configured to electrically connect the electrodes to the defibrillator, in which case it is preferred that, prior to use, the lead wires are substantially completely enclosed within the electrode assembly. The electrode assemblies may also include a release sheet, mounted on a surface of each electrode to protect the electrodes, the release sheet being configured to be removable when the electrode is positioned adjacent the patient""s skin.
Each of the aspects of the invention discussed above may include any desired combination of the features that are described above.
Other features and advantages of the invention will be apparent from the description and drawings, and from the claims.